One-Part Cold Applied System

A one-part cold-applied sealant, typically a moisture-curing polyurethane such as Sikaflex or Sea-Kar. It skins within the hour, but it cures from the surface inwards at roughly 3.5mm a day, so a deep joint takes days rather than hours and cold weather extends that considerably. Suitable where an extended cure is acceptable and there is no fuel exposure, since the common one-part polyurethanes carry no fuel-resistant classification. We offer alternatives to suit your budget and requirements.

Key benefits:

• Cost-effective at large volumes
• One-part: simple application
• Suitable for ports, warehouses, distribution centres
• Skins within the hour, then cures at about 3.5mm a day

Applications: Ports, sea works, warehouses, distribution centres, non-aviation commercial surfaces.

A one-part sealant is quick to apply and slow to cure all the way through, because it draws moisture from the air and cures from the surface inwards. At about 3.5mm a day, a joint 16mm deep takes four to five days to cure in mild weather and close to a week in a Kent winter. The work is planned so the joints stay clear of traffic for that long, or a two-part system is used where the surface has to reopen the same shift.

The joint matters as much as the material. The bead should be about twice as wide as it is deep and bonded to the two joint faces only, with a backer rod underneath so it cannot stick to the bottom of the slot and tear. A joint sealed deeper than it needs to be adds days to the cure for no benefit.

Unopened cartridges have a dated shelf life and an opened one has almost none, so batch dates are checked on delivery rather than at the point of use. More detail is in what is a one-part cold applied system?